1. Field of the Invention
The present invention is related to a power amplifying circuit, and more particularly to a power amplifying circuit having a biasing signal at the input terminal, and an amplifying method thereof.
2. Description of the Prior Art
In modern wireless communication systems, power amplifying units are utilized for amplifying an output signal to a reasonable amplitude. Thus, the power amplifying units are the most power consuming devices in wireless communication systems. An ideal power amplifying unit is capable of adaptively adjusting the output power according to requirements to reduce the power consumption of the system. According to a prior art method, power efficiency is increased by adjusting the power source of the power amplifying unit to adjust the output power of the power amplifying unit. Therefore, if high output power is required, the power source of the power amplifying unit will be increased; and if low output power is required, then the power source of the power amplifying unit will be decreased.